Prior-art terminals, such as mobile stations or media devices, use different electronic calendars. The users add calendar notes to the appropriate locations in the calendars. It is often useful to share the information in the calendar with other people. For instance, when deciding on meeting schedules, travel or vacation times among several persons, it would be beneficial that the information in the personal calendars of the persons were available. By sharing calendar content, it would be easy and fast to find a meeting time, for instance, that is suitable for all parties without time-consuming telephone calls or e-mail messages.
Sharing calendar content with others is, however, often impossible, because calendars usually also contain confidential information that is not meant for others to see. A person does not want to reveal personal appointments during work-related communication or work-related appointments in connection with free time.